208685421 has 48 divisors (see below), whose sum is σ = 377395200. Its totient is φ = 108347904.

The previous prime is 208685381. The next prime is 208685431. The reversal of 208685421 is 124586802.

It is not a de Polignac number, because 208685421 - 2⁶ = 208685357 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208685431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 27700 + ... + 34418.

It is an arithmetic number, because the mean of its divisors is an integer number (7862400).

Almost surely, 2^208685421 is an apocalyptic number.

208685421 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

208685421 is a deficient number, since it is larger than the sum of its proper divisors (168709779).

208685421 is a wasteful number, since it uses less digits than its factorization.

208685421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6778 (or 6775 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 208685421 is about 14445.9482554798. The cubic root of 208685421 is about 593.1493196639.

The spelling of 208685421 in words is "two hundred eight million, six hundred eighty-five thousand, four hundred twenty-one".